Effects of Seasonal Rest Grazing on Soil Aggregate Stability and Organic Carbon in Alpine Grasslands in Northern Xizang

Land Degradation and Development, Journal Year: 2025, Volume and Issue: unknown

Published: March 18, 2025

ABSTRACT Seasonal rest grazing is key to the recovery and sustainable use of alpine grasslands in northern Xizang. Postgrazing changes soil structure organic carbon stability are indicative grassland recovery. However, mechanisms by which seasonal affects these properties remain unclear. This study examined subjected 5 years assess its impact on plant community traits, aggregate stability, content. The results show that (1) compared with traditional grazing, significantly improved height, coverage, undecomposed litterfall, biomass while also substantially reducing root–crown ratio. (2) resulted a pronounced increase water content, whereas bulk density, pH, carbon, total nitrogen carbon–nitrogen ratio decreased. (3) enhanced increased proportion content macro‐aggregate (> 0.25 mm), but contents micro‐aggregates (0.25–0.053 silt + clay particles (< 0.053 their associated (4) Redundancy analysis structural equation modeling indicated effects each aggregate, physical properties, chemical after were more significant than those was factor affecting In conclusion, can improve productivity plays an important role ecosystem maintenance fixation, related altitude.

Language: Английский

Chemical Composition and Cytotoxicity Evaluation of Artemisia judaica L. Essential Oil from Saudi Arabia

Molecules, Journal Year: 2024, Volume and Issue: 29(12), P. 2882 - 2882

Published: June 18, 2024

Gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS) analyses were conducted on essential oil extracted from Saudi Arabian Artemisia judaica L. (A. judaica) aerial parts, resulting in the identification of 58 constituents, representing 93.0% total composition. The primarily consisted monoterpenes (38.6%), sesquiterpenes (14.1%), other compounds such as ethyl esters cyclic ketones (40.3%). main components identified piperitone (16.5%), cinnamate (12.9%), camphor (9.7%). Multivariate statistical (MVAs), including principal component analysis (PCA) agglomerative hierarchical clustering (AHC) analysis, employed to compare chemical makeup this with 20 A. oils various regions. study revealed distinct clusters, highlighting unique chemotypes geographic variations. Particularly, current demonstrated a specialized profile significant concentrations specific compounds, contributing significantly its distinctiveness. Further cytotoxicity testing RAW264.7 macrophages suggested that below μg/mL are suitable for future pharmacological investigations. This provides valuable insights into diversity, variations, potential biomedical applications these oils.

Language: Английский